Talk of "gutter politics" from Simpson - while Ms Dobson looked on seemingly unruffled - erupted in a shouting match between rival supporters after Mr Simpson was confirmed to have held on to his seat for a second time.

He polled 15,430 to Ms Dobson's 13,166 to return him as the area's MP, a role he has fulfilled since 2005.

"This campaign has stooped to the gutter, I won't say any more as the truth really hurts," Simpson said in his victory speech.

His supporters started to sing in triumph before storming out of the declaration room while the other candidates and their supporters stayed to listen to the other speeches.

However, Ms Dobson quipped: "I'll be back, as Arnold Schwarzenegger would say.

"I can honestly say that I can look the people of this constituency straight in the eye and tell them that we ran a purely positive campaign."

Afterwards Mr Simpson said: "I have been involved in politics for 18 years and I have never seen anything as despicable and personal.

"It's an awful situation where someone adopts an international family and where that family is lambasted, maybe because of their colour or for whatever."

The irony of the unionist pact was that Simpson voted for Ulster Unionist Tom Elliott in Fermanagh/South Tyrone.

He added: "Yes, there is a pact in Fermanagh and South Tyrone. I'm 20 yards into Fermanagh and South Tyrone (constituency) and I voted for Tom Elliott because that was the agreement.

"There was no pact here to start with. Whenever it was announced I had won, the Ulster Unionists seemed to lose it." He hinted he was considering action against those who had abused his children on Facebook during the election.

There was ill-feeling on the nationalist side, too.

SDLP veteran Dolores Kelly described it as "one of the dirtiest elections I have ever taken part in".

She also suggested that teacher Catherine Seeley of Sinn Fein needed to go back to school if she really believed her comment that "Upper Bann is a safe seat for no one".

Ms Seeley came in third with 11,593 votes, while Ms Kelly, stung by Sinn Fein's "lend us your vote" call to constituents, said that even their joint vote could not have beaten Simpson.

But that claim proved to be a bit off, as the joint nationalist vote of 15,831 would have been enough to beat Mr Simpson by 401 votes.